I tried low amount of meth how long will it be in my saliva

Few days: It will likely only test positive in your saliva for a few days as long as it is only a "low amount." and it was a one time thing. The longer you use most drugs the longer it will produce a positive result in tests. Saliva tests, however, are not as predictable or reliable as urine tests so it might be different each time you take a test. Good luck!